Connected aircraft are becoming the new standard for retrofit operations as well as new deliveries. However, the fully connected aircraft of the future may come with built-in cybersecurity risks: namely, that exploitable vulnerabilities may be lying dormant within the delivered hardware or software. One technique for discovering potential vulnerabilities within connected avionics systems involves network fuzzing of the inputs to those systems. Fuzzing involves the generation of large quantities of test cases based on mutations of the standard inputs. The test cases may be logged so that the tester may repeat tests or analyze a test case, or sequence thereof, responsible for a system error. Fuzzing during initial testing may provide a preemptive defense against attackers using the same technique to probe systems for potential weaknesses.